Emerging and Evolving Concepts in Cancer Immunotherapy Imaging.

Criteria based on measurements of lesion diameter at CT have guided treatment with historical therapies due to the strong association between tumor size and survival. Clinical experience with immune checkpoint modulators shows that editing immune system function can be effective in various solid tumors. Equally, novel immune-related phenomena accompany this novel therapeutic paradigm. These effects of immunotherapy challenge the association of tumor size with response or progression and include risks and adverse events that present new demands for imaging to guide treatment decisions. Emerging and evolving approaches to immunotherapy highlight further key issues for imaging evaluation, such as dissociated response following local administration of immune checkpoint modulators, pseudoprogression due to immune infiltration in the tumor environment, and premature death due to hyperprogression. Research that may offer tools for radiologists to meet these challenges is reviewed. Different modalities are discussed, including immuno-PET, as well as new applications of CT, MRI, and fluorodeoxyglucose PET, such as radiomics and imaging of hematopoietic tissues or anthropometric characteristics. Multilevel integration of imaging and other biomarkers may improve clinical guidance for immunotherapies and provide theranostic opportunities.

High serum LDH and liver metastases are the dominant predictors of primary cancer resistance to anti-PD(L)1 immunotherapy.

AIM: Anti-PD-(L)1 immunotherapies improve survival in multiple cancers but remain ineffective for most patients. We applied machine-learning algorithms and multivariate analyses on baseline medical data to estimate their relative impact on overall survival (OS) upon anti-PD-(L)1 monotherapies. METHOD: This prognostic/predictive study retrospectively analysed 33 baseline routine medical variables derived from computed tomography (CT) images, clinical and biological meta-data. 695 patients with a diagnosis of advanced cancer were treated in prospective clinical trials in a single tertiary cancer centre in 3 cohorts including systemic anti-PD-(L)1 (251, 235 patients) versus other systemic therapies (209 patients). A random forest model combined variables to identify the combination (signature) which best estimated OS in patients treated with immunotherapy. The performance for estimating OS [95%CI] was measured using Kaplan-Meier Analysis and Log-Rank test. RESULTS: Elevated serum lactate dehydrogenase (LDHhi) and presence of liver metastases (LM+) were dominant and independent predictors of short OS in independent cohorts of melanoma and non-melanoma solid tumours. Overall, LDHhiLM+ patients treated with anti-PD-(L)1 monotherapy had a poorer outcome (median OS: 3.1[2.4-7.8] months]) compared to LDHlowLM-patients (median OS: 15.3[8.9-NA] months; P < 0.0001). The OS of LDHlowLM-patients treated with immunotherapy was 28.8[17.9-NA] months (vs 13.1[10.8-18.5], P = 0.02) in the overall population and 30.3[19.93-NA] months (vs 14.1[8.69-NA], P = 0.0013) in patients with melanoma. CONCLUSION: LDHhiLM+ status identifies patients who shall not benefit from anti-PD-(L)1 monotherapy. It could be used in clinical trials to stratify patients and eventually address this specific medical need.

Cabozantinib-nivolumab sequence in metastatic renal cell carcinoma: The CABIR study.

Nivolumab and cabozantinib are approved agents in mRCC patients after sunitinib/pazopanib (TKI) failure. However, the optimal sequence, cabozantinib then nivolumab (CN) or nivolumab then cabozantinib (NC), is still unknown. The CABIR study aimed to identify the optimal sequence between CN and NC after frontline VEGFR-TKI. In this multicenter retrospective study, we collected data from mRCC pts receiving CN or NC, after frontline VEGFR-TKI. A propensity score (PrS) was calculated to manage bias selection, and sequence comparisons were carried out with a cox model on a matched sample 1:1. The primary endpoint was progression-free survival (PFS) from the start of second line to progression in third line (PFS2-3 ). Key secondary endpoints included overall survival from second line (OS2 ). Out of 139 included mRCC patients, 38 (27%) and 101 (73%) received CN and NC, respectively. Overlap in PrS allowed 1:1 matching for each CN pts, with characteristics well balanced. For both PFS2-3 and OS2 , NC sequence was superior to CN (PFS2-3 : HR = 0.58 [0.34-0.98], P = .043; OS2 : 0.66 [0.42-1.05], P = .080). Superior PFS2-3 was in patients treated between 6 and 18 months with prior VEGFR-TKI (P = .019) and was driven by a higher PFSL3 with cabozantinib when given after nivolumab (P < .001). The CABIR study shows a prolonged PFS of the NC sequence compared to CN in mRCC after first line VEGFR-TKI failure. The data suggest that cabozantinib may be more effective than nivolumab in the third-line setting, possibly related to an ability of cabozantinib to overcome resistance to PD-1 blockade.

Outcomes of patients with cancer and sarcoid-like granulomatosis associated with immune checkpoint inhibitors: A case-control study.

PURPOSE: Sarcoid-like granulomatosis (SLG) reaction caused by immunotherapy remains poorly understood. This study aims to investigate the outcome of patients with cancer and SLG associated with immunotherapy. PATIENTS AND METHODS: Between April 2016 and June 2020, 434 patients with immunological adverse events were screened from the ImmunoTOX assessment board of Gustave Roussy, an academic cancer centre in France. Among them, 28 patients had SLG associated with immunotherapy (SLG cohort) and 406 patients had other immunological adverse events (control cohort). Clinical characteristics and outcome of patients were compared from SLG and control cohort. RESULTS: The SLG cohort consisted of 28 patients, 14 women and 14 men, with the median (range) age of 56.5 (28.7-75.3) years. Patients in the SLG cohort with sarcoidosis were asymptomatic (only radiographical finding) in 13 (46.4%) cases; otherwise, the most frequent symptoms were dyspnoea in 8 (28.6%) patients and cough in 5 (17.8%) patients. The computerised tomography scan found sarcoidosis localisations in mediastinal or peri-hilar thoracic lymph nodes in 26 (92.9%) patients, and lung parenchymal involvement was found in 14 (50.0%) patients. The radiographic Scadding stages for sarcoidosis classification were distributed in stages 0, I, II, III and IV in 2 patients (7.1%), 13 patients (46.4%), 11 patients (39.3%), 1 patient (3.6%) and 1 patient (3.6%), respectively. Compared with patients with other immunological toxicities (cohort control), patients with sarcoidosis presented most frequently with melanoma (75.0% versus 21.9% of patients; p < 0.001) and more often received combined therapies of anti-programmed cell death 1 plus anti-cytotoxic T-lymphocyte antigen 4 protein (46.4% versus 12.6% of patients; p = 0.002). Patients with sarcoidosis had an improved overall survival (OS); the median OS was not reached in the SLG cohort and 40.4 months in the control cohort, hazard ratio = 0.232 (95% confidence interval: 0.086-0.630) (p = 0.002). CONCLUSION: Sarcoidosis-like reactions in patients receiving immunotherapy were reported as non-severe immunological reactions in most cases and were correlated with improved OS. SLG should not be misdiagnosed as tumour progression in patients receiving immunotherapy treatment for cancer.

Clinical progression is associated with poor prognosis whatever the treatment line in metastatic castration resistant prostate cancer: The CATS international database.

AIM OF THE STUDY: Our goal was to evaluate the impact of progression type (prostate-specific antigen [PSA] only, radiological or clinical) at initiation of first-, second- and third life-extending therapy (LET) on treatment outcomes in metastatic castration-resistant prostate cancer (mCRPC) patients, by performing a post-hoc analysis using data from the CATS international registry. METHODS: The 669 consecutive mCRPC patients of the CATS registry were classified according to their type of progression at initiation of each LET: PSA only (PSA-p), radiological (±PSA) (Radio-p); or clinical (±PSA, ±radiological) progression (Clin-p). Overall survival (OS), the primary endpoint, was calculated from initiation of the first-, second- and third-LET to death for each sequence. RESULTS: Median OS was shorter in the Clin-p group compared with the PSA-p group (14-month difference in first line; around 7-month difference in second- and third line). Shorter progression-free survival (PFS) was also observed in Clin-p patients, whatever the treatment is. Clinical progression seemed to be associated with a shorter duration of therapy with androgen receptor-targeted therapy (ART) compared with taxanes. CONCLUSIONS: Clinical progression at initiation of a LET is associated with poor outcomes including shorter PFS and OS as well as clinical and biological features of aggressive disease. Stratifying patients in clinical trials according to disease progression type may prevent selection bias and data heterogeneity. In daily practice, first signs of clinical progression may prompt physicians to consider starting a new LET, independently of PSA levels.

Resident memory T cells, critical components in tumor immunology.

CD8+ T lymphocytes are the major anti-tumor effector cells. Most cancer immunotherapeutic approaches seek to amplify cytotoxic T lymphocytes (CTL) specific to malignant cells. A recently identified subpopulation of memory CD8+ T cells, named tissue-resident memory T (TRM) cells, persists in peripheral tissues and does not recirculate. This T-cell subset is considered an independent memory T-cell lineage with a specific profile of transcription factors, including Runx3+, Notch+, Hobit+, Blimp1+, BATF+, AHR+, EOMESneg and Tbetlow. It is defined by expression of CD103 (αE(CD103)ß7) and CD49a (VLA-1 or α1ß1) integrins and C-type lectin CD69, which are most likely involved in retention of TRM cells in non-lymphoid tissues, including solid tumors. CD103 binds to the epithelial cell marker E-cadherin, thereby favoring the location and retention of TRM in epithelial tumor regions in close contact with malignant cells. The CD103-E-cadherin interaction is required for polarized exocytosis of lytic granules, in particular, when ICAM-1 expression on cancer cells is missing, leading to target cell death. TRM cells also express high levels of granzyme B, IFNγ and TNFα, supporting their cytotoxic features. Moreover, the local route of immunization targeting tissue dendritic cells (DC), and the presence of environmental factors (i.e. TGF-ß, IL-33 and IL-15), promote differentiation of this T-cell subtype. In both spontaneous tumor models and engrafted tumors, natural TRM cells or cancer-vaccine-induced TRM directly control tumor growth. In line with these results, TRM infiltration into various human cancers, including lung cancer, are correlated with better clinical outcome in both univariate and multivariate analyses independently of CD8+ T cells. TRM cells also predominantly express checkpoint receptors such as PD-1, CTLA-4 and Tim-3. Blockade of PD-1 with neutralizing antibodies on TRM cells isolated from human lung cancer promotes cytolytic activity toward autologous tumor cells. Thus, TRM cells appear to represent important components in tumor immune surveillance. Their induction by cancer vaccines or other immunotherapeutic approaches may be critical for the success of these treatments. Several arguments, such as their close contact with tumor cells, dominant expression of checkpoint receptors and their recognition of cancer cells, strongly suggest that they may be involved in the success of immune checkpoint inhibitors in various cancers.

Targeting Resident Memory T Cells for Cancer Immunotherapy.

A novel population of memory CD8+ T cells called resident memory T cells (TRM) has been identified based on their phenotype (CD103, CD69) and on their local tissue residency without recirculating in the blood. These cells have been implicated in protective immune response against pathogens in both animal models and humans. Their role in cancer is just emerging as a key player in tumor immunosurveillance. Many properties of these cells suggest that they could control tumor growth: (i) they respond much faster to reexposure to cognate antigen than circulating memory cells, (ii) they express high levels of cytotoxic molecules, and (iii) they are enriched in tumor-specific T cells in close contact with tumor cells. TRM are present in many human cancers and are associated with a good clinical outcome independently of the infiltration of CD8+ T cells. It has been recently shown that the efficacy of cancer vaccines depends on their ability to elicit TRM. In adoptive cell therapy, the transfer of cells with the ability to establish TRM at the tumor site correlates with the potency of this approach. Interestingly, TRM express immune checkpoint molecules and preliminary data showed that they could expand early during anti-PD-1 treatment, and thus be considered as a surrogate marker of response to immunotherapy. Some cues to better expand these cells in vivo and improve the success of cancer immunotherapy include using mucosal routes of immunization, targeting subpopulations of dendritic cells as well as local signal at the mucosal site to recruit them in mucosal tissue.

Sequencing of Taxanes and New Androgen-targeted Therapies in Metastatic Castration-resistant Prostate Cancer: Results of the International Multicentre Retrospective CATS Database.

BACKGROUND: The optimal sequence of life-extending therapies in metastatic castration-resistant prostate cancer (mCRPC) is unknown. OBJECTIVE: To evaluate outcomes among mCRPC patients treated with docetaxel (DOC), cabazitaxel (CABA), and a novel androgen receptor-targeted agent (ART; abiraterone acetate or enzalutamide) according to three different sequences. DESIGN, SETTING, AND PARTICIPANTS: Data from 669 consecutive mCRPC patients were retrospectively collected between November 2012 and October 2016. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint was the prostate-specific antigen (PSA) response (decrease ≥50% from baseline) to each therapy. Secondary endpoints included best clinical benefit, time to PSA progression, radiological progression-free survival (rPFS), overall survival (OS), and toxicity. RESULTS AND LIMITATIONS: A total of 158 patients received DOC→CABA→ART (group 1), 456 received DOC→ART→CABA (group 2), and 55 received ART→DOC→CABA (group 3). At baseline, PSA progression only and Gleason <8 were more common in group 3. PSA response on DOC was lower in group 3 than in other groups (p=0.02) and PSA response on CABA was higher in the second than in the third line (p=0.001). In Group 3, rPFS on ART (6.6 mo) and DOC (9.2 mo) was also shorter than in the other groups. OS calculated from the first life-extending therapy reached 34.8, 35.8, and 28.9 mo in groups 1, 2 and 3, respectively (p=0.007). Toxicity was comparable between the arms. The main limitations of the trial are its retrospective design and the low number of patients in group 3. CONCLUSIONS: In this retrospective trial, sequencing of DOC, CABA, and one ART, was associated with median OS of up to 35.8 mo. CABA seemed to retain its activity regardless of treatment sequence. DOC activity after ART appeared to be reduced, but the data are insufficient to conclude that cross-resistance occurs. PATIENT SUMMARY: The order of drugs administered to patients with metastatic castration-resistant prostate cancer could impact their efficacy, with cabazitaxel appearing to retain its activity whatever the therapeutic sequence.